Puzzle of low temperature phase of α-(ET)2 salts

α-(ET)2 salts split into two groups: one superconducting and another with mysterious low temperature phase (LTP). The LTP does not exhibit X-ray signiture of conventional CDW or magnetic one for SDW. But the magnetic phase diagram suggests strongly a kind of CDW. We have analysed the threshold electric field of unconventional CDW (UCDW) both for H=0 and H≠0. The threshold electric field for UCDW with H=0 and for 3D weak-pinning limit describes reasonably well the one determined in α-(ET)2KHg(SCH)4. The result for H≠0 is also presented. We propose that the LTP in α-(ET)2 salts is most likely UCDW.